Biogenic habitats & the engineers behind it

This week, we will talk about another topic related to sessile organisms. Biogenic reefs or broader biogenic habitats are habitats which are changed in their physical state by or through the presence of ecosystem engineers.   

Such habitats altered by ecosystem engineers present a new habitat structure where species find shelter. As these habitats potentially provide a home to species other than the surrounding environment, local biodiversity increases. Therefore, those habitats with increased complexity are known as biogenic habitats.   

The habitat-altering species are ecosystem engineers but are often incorrectly referred to as bioengineers.  

Particularly in marine environments, we can find plenty of native and alien ecosystem engineers. As an invertebrate taxonomist, we are naturally more interested in spinless organisms forming Biogenic habitats. Habitats formed by sessile invertebrates provide new hard substrate through secretion and accumulation of minerals. Hence, in agreement with O’Sullivan et al. (2017), we define biogenic reefs as an accumulation of dead or alive hard-bodied animals or shells and tubes of soft-bodied invertebrates.   

Through the 3-dimensional structure, biogenic reefs provide refuge for small and juvenile organisms. Further, in soft bottom habitat reefs can attract species which are usually not associated with sand or mudflat. As unselective filter feeders, most reef-forming invertebrates remove microorganisms and biological material from the water column, often improving water quality. Reefs also contribute to coastal and shoreline protection by reducing wave impact as well as securing sediment. Also, it is reported that the seeding of native species reefs can reduce the recruitment of invasive species.  

According to surveys of local fishermen around New Zealand, 588 areas were marked as possible biogenic habitats. Around 330 were classified as biogenic habitats in 2016, and at least 50 of these habitats are biogenic reefs.  

Of all these habitats, only 35 were surveyed during two expeditions in the year 2018. Over 900 species, including 95 undescribed species, were counted. Hence, it is time that we are surveying all biogenic habitats. We at Ocean Wolf suggest and advocate for an initial non-invasive survey using tools like eDNA (for example, working with our colleagues from Sequench) and AI (for example, our friends from FanthomNet: https://lnkd.in/gQMGQdqf) followed by a precise taxonomic investigation in identified Key areas.   

Reach out at www.ocean-wolf.com (paul@ocean-wolf.com) if you want to know more.  

Below you see biogenic reefs formed by NZ native ecosystem engineer Spirobranchus cariniferus.